Adding Two Digit Numbers

1
Adding Two Digit Numbers

• Susie Wellert
• Wellert Link Page
• Northern Michigan University

2
Adding Multiples of Ten

• This is how we show 101020

Each bundle of sticks equals 10 so two bundles of
10 equals 20.
3
Continued

• Here is another way that we can show 101020

Click here for some practice.
4
Expanded Form

• What number is this?

It is the number 34. We are going to write 34 in
a new way now. How many are in the tens? There
are 3 tens, that equals 30. Plus how many ones?
There are 4 ones. When you add them together they
make 34.
5
Expanded Form Continued

• So now we can write 34 in a new way
• 34 3 tens 4
• 34 30 4
• 34 30 4 is called expanded form. Click here
  to do a worksheet for practice.

6
Simplest Form

• Do you know what the simplest name is for the
  answer to this
• 40 7 ___

The simplest name is 47.
7
Putting It All Together

• Now we have all the pieces that we need to add
  two digit numbers.
• Just follow the example below

All you have to do is add the bundles of sticks
together then add the tally marks together to
find how many are in all.
8

• Now you know how to add two digit numbers!!
  Click here to take the quiz.

To check your answers click on each of these,
worksheet1, worksheet2 and the quiz.